/**
 * Copyright (C) 2008 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.inject.spi;

import static com.google.common.base.Preconditions.checkNotNull;

import com.google.common.collect.ImmutableList;
import com.google.inject.Binder;
import com.google.inject.matcher.Matcher;

import org.aopalliance.intercept.MethodInterceptor;

import java.lang.reflect.Method;
import java.util.List;

/**
 * Registration of interceptors for matching methods of matching classes. Instances are created
 * explicitly in a module using {@link com.google.inject.Binder#bindInterceptor(
 * Matcher, Matcher, MethodInterceptor[]) bindInterceptor()} statements:
 * <pre>
 *     bindInterceptor(Matchers.subclassesOf(MyAction.class),
 *         Matchers.annotatedWith(Transactional.class),
 *         new MyTransactionInterceptor());</pre>
 *
 * or from an injectable type listener using {@link TypeEncounter#bindInterceptor(Matcher,
 * org.aopalliance.intercept.MethodInterceptor[]) TypeEncounter.bindInterceptor()}.
 *
 * @author jessewilson@google.com (Jesse Wilson)
 * @since 2.0
 */
public final class InterceptorBinding implements Element {
    private final Object source;
    private final Matcher<? super Class<?>> classMatcher;
    private final Matcher<? super Method> methodMatcher;
    private final ImmutableList<MethodInterceptor> interceptors;

    InterceptorBinding(Object source, Matcher<? super Class<?>> classMatcher, Matcher<? super Method> methodMatcher, MethodInterceptor[] interceptors) {
        this.source = checkNotNull(source, "source");
        this.classMatcher = checkNotNull(classMatcher, "classMatcher");
        this.methodMatcher = checkNotNull(methodMatcher, "methodMatcher");
        this.interceptors = ImmutableList.copyOf(interceptors);
    }

    public Object getSource() {
        return source;
    }

    public Matcher<? super Class<?>> getClassMatcher() {
        return classMatcher;
    }

    public Matcher<? super Method> getMethodMatcher() {
        return methodMatcher;
    }

    public List<MethodInterceptor> getInterceptors() {
        return interceptors;
    }

    public <T> T acceptVisitor(ElementVisitor<T> visitor) {
        return visitor.visit(this);
    }

    public void applyTo(Binder binder) {
        binder.withSource(getSource()).bindInterceptor(classMatcher, methodMatcher, interceptors.toArray(new MethodInterceptor[interceptors.size()]));
    }
}
